1. Field of the Invention
The present invention relates to a high-speed data dedicated system. More particularly, the present invention relates to a method and apparatus for allocating a Unicast Access Terminal Identifier (UATI) to an Access Terminal) in a 1× Evolution Data Only (1× EV-DO) system.
2. Description of the Related Art
A code division multiple access (CDMA) technique is a spread spectrum communication technique capable of supporting more users with limited frequency resources. CDMA communication systems which are mainly based on voice communication have developed from International Standard (IS)-95A and 95B supporting a relative low-speed data transmission rate of a maximum of 64 Kbps to IS-95C supporting a data transmission rate of 144 Kbps. IS-95C is referred to as “CDMA2000 1×”, and supports streaming type multimedia services such as a set of services provided through wireless multimedia platforms such as Java, Brew, audio on demand, video on demand, and so on as well as a text service.
A CDMA2000 1× EV-DO system based on the CDMA 1× system supports a data transmission rate of a maximum of 2.4 Mbps that is 16 times as high as the data transmission rate supported by the CDMA2000 1× system, supports bi-directional data transmission as well as a high-speed Internet search during mobile communication, and simultaneously provides more users with high-speed data services at low cost because the capacity of the CDMA2000 1× EV-DO system is nearly 5 times the capacity of the CDMA2000 1× system. In the CDMA2000 1× EV-DO system, EV refers to the evolution of the CDMA2000 1×, and DO refers to the support of data only rather than voice. The 1× EV-DO standard is referred to as IS-856.
The 1× EV-DO granted by the International Telecommunication Union (ITU) can provide sufficient multimedia content in various fields such as wireless Internet access, real-time traffic information, wireless live broadcasts, television, movies, music videos, Internet games, mobile commerce (m-commerce), and so on using an improved data transmission rate and capacity. The 1× EV-DO system uses a CDMA2000 system base, and can be implemented by replacing an access network transceiver system. An access network transceiver system uses the structure of a wireless Internet protocol (IP) for directly accessing a packet network and does not use a circuit-switched mobile switching center (MSC). Thus, a packet data service can be maximized.
In order to distinguish among Access Terminals (ATs), other systems such as the CDMA2000 1× system, and so on use permanently assigned Mobile IDentifiers (MIDs) such as an International Mobile Subscriber Identifier (IMSI), an Electronic Serial Number (ESN), a Mobile Identification Number (MIN), and so on. In contrast, the 1× EV-DO system uses a Unicast Access Terminal Identifier (UATI) serving as a temporary identifier allocated in a unit of a subnet corresponding to a predetermined geographical region.
An AT seeking access to the 1× EV-DO system receives a UATI allocated from the system after setting up a radio traffic channel with a base station. The system allows Internet access to be enabled through an IP address allocation procedure, a user authentication procedure, and the like after an authentication operation is performed for the AT with the UATI. However, when the AT moves to a new subnet while the UATI is allocated to the AT, the system determines that the UATI allocation has failed because the conventional 1× EV-DO system processes the UATI allocation according to a limited individual subnet. Thus, there is a problem in that the UATI allocation fails when the AT moves to the new subnet when the UATI is allocated to the AT.